The presidential campaign of Hillary Clinton this week attempted to further distance itself from the Clinton Foundation, a charitable group founded by her husband, former President Bill Clinton. The group has done charity work around the globe but has increasingly become a liability for Clinton as she seeks the presidency.

What is the Clinton Foundation?

Established in 1997, the Clinton Foundation is a non-profit corporation that funds global philanthropic work on issues such as global health, disaster relief, women's rights, economic growth and climate change.

Since its creation, the group has raised more than $2 billion from a large global network that includes foreign governments, organizations and individuals, including some with questionable human rights records.

FILE - Former U.S. President Bill Clinton attends a news conference after visiting social projects supported by his foundation in Lima, June 8, 2010.

Why is its funding controversial?

Under U.S. law, foreign donors and countries are ineligible to give money to U.S. political campaigns. But by donating to the Clinton Foundation, some say those donors are exploiting a workaround that in effect buys them influence with the Clintons.

Before becoming secretary of state in 2009, Hillary Clinton agreed to separate her activities at the State Department from those at the Clinton Foundation. But conservative groups have long been suspicious that there was still an overlap.

Why is that an issue now?

Recently unveiled emails show that State Department aides to Hillary Clinton looked into doing favors for Clinton Foundation donors or people who were linked to donors, in what was for many a confirmation of overlap between the two entities.

What exactly do the emails prove?

Shortly after Clinton stepped down as secretary of state in 2013, the State Department expressed interest in, but didn't follow through with, buying real estate from a Nigerian company run by a man whose brother donated at least $1 million to the Clinton Foundation.

FILE - In this Oct. 18, 2011, file photo, then-Secretary of State Hillary Rodham Clinton checks her Blackberry from a desk inside a C-17 military plane upon her departure from Malta, in the Mediterranean Sea, bound for Tripoli, Libya.

In another instance, a senior Clinton Foundation official, Doug Band, asked a top Clinton aide at the State Department about possibly getting a job for an individual whom he said it was "important to take care of." The individual, whose name was redacted in the email, was subsequently sent "options," according to a reply by Huma Abedin, the State Department aide. The outcome of the apparent job placement effort is not clear.

Are any of those actions illegal?

It's not clear.

But what was revealed in the emails does suggest a possible conflict of interest, according to Scott Amey, general counsel at the non-partisan Project on Government Oversight watchdog.

"I doubt my emails were going to get responded to by Huma Abedin," Amey said. "And at that point, you've created a system that allows favoritism."

But at this point, it does not appear that Hillary Clinton was implicated directly in any of the emails.

Is that behavior out of the ordinary?

Not really, Amey says.

"I think this is the kind of thing that happens every day in Washington, D.C.," he said, citing the outsized influence of wealthy lobbying groups and the tendency for top government officials to go back and forth between working in public and private positions.

"You always have to worry about whether people are getting some sort of unfair competitive advantage that is skewing the system or that isn't in the public interest," he added.

Republican presidential candidate Donald Trump says the emails are evidence that the Clintons are corrupt, and that donors essentially engaged in inappropriate "pay to play" practices with them.

The accusation fits a longstanding attack pattern by conservatives, who have for decades tried to paint the Clintons as the ultimate insiders who have gotten wealthy by their connections to Wall Street billionaires.

How has Clinton responded?

The Clinton campaign has firmly denied any wrongdoing, saying that any decisions by State Department officials were made without considering the influence of donors.

But the Clintons have also been forced to distance themselves from their foundation. This week, Bill Clinton said the organization would no longer accept foreign or corporate money and that he would resign from its board if Hillary Clinton is elected.

Can the Clintons really separate themselves enough?

Probably not, says Mark Rom, a professor of public policy at Georgetown University.

"When your name is on it, it's pretty hard to do that," he said. "Even if you really are entirely separate, and there is no communication at all, people will still say that they gave to the Clinton Foundation."

There have been increasing calls for the Clintons to shut down the organization altogether, and those calls seem likely to only grow louder as Election Day approaches.

Where does it go from here?

The controversy probably won't go away, since Trump seems determined to make it a key campaign issue. There could also be more revelations about links between the Clinton Foundation and the State Department.

"There's bound to be more," said political scientist Larry Sabato. "The opposition party always saves things for the last few weeks of a campaign."